package com.yunhe.gateway.handler;

import java.util.HashMap;
import java.util.Map;

import com.yunhe.gateway.constant.ErrorCode;
import org.springframework.boot.autoconfigure.web.ErrorProperties;
import org.springframework.boot.autoconfigure.web.ResourceProperties;
import org.springframework.boot.autoconfigure.web.reactive.error.DefaultErrorWebExceptionHandler;
import org.springframework.boot.web.reactive.error.ErrorAttributes;
import org.springframework.context.ApplicationContext;
import org.springframework.http.HttpStatus;
import org.springframework.web.reactive.function.server.RequestPredicates;
import org.springframework.web.reactive.function.server.RouterFunction;
import org.springframework.web.reactive.function.server.RouterFunctions;
import org.springframework.web.reactive.function.server.ServerRequest;
import org.springframework.web.reactive.function.server.ServerResponse;
import org.springframework.web.server.ResponseStatusException;

/**
 * 自定义异常处理
 * @author liuronglei
 */
public class JsonExceptionHandler extends DefaultErrorWebExceptionHandler {

    public JsonExceptionHandler(ErrorAttributes errorAttributes, ResourceProperties resourceProperties,
                                ErrorProperties errorProperties, ApplicationContext applicationContext) {
        super(errorAttributes, resourceProperties, errorProperties, applicationContext);
    }

    /**
     * 获取异常属性
     */
    @Override
    protected Map<String, Object> getErrorAttributes(ServerRequest request, boolean includeStackTrace) {
        Throwable error = super.getError(request);
        if (error instanceof org.springframework.cloud.gateway.support.NotFoundException) {
            return response(HttpStatus.NOT_FOUND.value(), ErrorCode.CODE.SERVICE_NOTFOUND.value(), ErrorCode.CODE.SERVICE_NOTFOUND.title());
        } else if (error instanceof ResponseStatusException && ((ResponseStatusException)error).getStatus().value() == 404) {
            return response(HttpStatus.NOT_FOUND.value(), ErrorCode.CODE.SERVICE_NOTFOUND.value(), ErrorCode.CODE.SERVICE_NOTFOUND.title());
        } else {
            return response(HttpStatus.INTERNAL_SERVER_ERROR.value(), ErrorCode.CODE.RESOURCE_ACCESS_ERROR.value(), ErrorCode.CODE.RESOURCE_ACCESS_ERROR.title());
        }
    }

    /**
     * 指定响应处理方法为JSON处理的方法
     * @param errorAttributes
     */
    @Override
    protected RouterFunction<ServerResponse> getRoutingFunction(ErrorAttributes errorAttributes) {
        return RouterFunctions.route(RequestPredicates.all(), this::renderErrorResponse);
    }

    /**
     * 根据code获取对应的HttpStatus
     * @param errorAttributes
     */
    @Override
    protected HttpStatus getHttpStatus(Map<String, Object> errorAttributes) {
        int statusCode = (int) errorAttributes.get("code");
        errorAttributes.remove("code");
        return HttpStatus.valueOf(statusCode);
    }

//    /**
//     * 构建异常信息
//     * @param request
//     * @param ex
//     * @return
//     */
//    private String buildMessage(ServerRequest request, Throwable ex) {
//        StringBuilder message = new StringBuilder("Failed to handle request [");
//        message.append(request.methodName());
//        message.append(" ");
//        message.append(request.uri());
//        message.append("]");
//        if (ex != null) {
//            message.append(": ");
//            message.append(ex.getMessage());
//        }
//        return message.toString();
//    }

    /**
     * 构建返回的JSON数据格式
     * @param errorCode 错误代码
     * @param errorMessage 错误信息
     * @return
     */
    private Map<String, Object> response(int statusCode, int errorCode, String errorMessage) {
        Map<String, Object> map = new HashMap<>();
        map.put("code", statusCode);
        map.put("errorCode", errorCode);
        map.put("errorMessage", errorMessage);
        return map;
    }

}